Fingerprint identifying module, fabrication method and driving method for the same, and display device

Abstract

A fingerprint identifying module, a fabrication method and a driving method for the same, and a display device are provided. The fingerprint identifying module includes a substrate, and a plurality of array-arranged fingerprint identifying modules provided on the substrate. Each of the fingerprint identifying modules includes a lower electrode, an upper electrode, and a photocurrent generating unit connected between the upper electrode and the lower electrode. The photocurrent generating unit includes a PN junction, one end of the PN junction being connected with the upper electrode, and the other end of the PN junction being connected with the lower electrode.

The invention claimed is: 
     
       1. A fingerprint identifying module, the fingerprint identifying module comprising:
 a substrate; 
 a plurality of fingerprint identifying modules on the substrate and arranged as an array, wherein each of the fingerprint identifying modules comprises:
 a lower electrode; 
 an upper electrode; and 
 a photocurrent generating unit between the upper electrode and the lower electrode and connected with both the upper electrode and the lower electrode, wherein the photocurrent generating unit comprises a PN junction, a scanning line and a sensing line, one end of the PN junction being connected with the upper electrode, and other end of the PN junction being connected with the lower electrode; and 
 
 a thin film transistor (TFT) between the upper electrode and the lower electrode, wherein the upper electrode is connected with a drain electrode of the TFT, the lower electrode is connected with the scanning line; the scanning line is configured for inputting a first fingerprint identifying voltage to the lower electrode while the TFT is turned on; the TFT is configured for being turned on under an effect of a gate voltage; a source electrode of the TFT is connected with the sensing line, and the sensing line is configured for inputting a second fingerprint identifying voltage to the source electrode of the TFT. 
 
     
     
       2. The fingerprint identifying module according to  claim 1 , wherein the lower electrode is configured for receiving the first fingerprint identifying voltage at fingerprint identifying stage, and receiving a touch signal at touch sensing stage. 
     
     
       3. The fingerprint identifying module according to  claim 1 , wherein a light-shielding layer is provided above the TFT. 
     
     
       4. The fingerprint identifying module according to  claim 3 , wherein the light-shielding layer is provided in a same layer as the upper electrode. 
     
     
       5. The fingerprint identifying module according to  claim 1 , wherein a conductive thin film is provided on an end surface of one end of the PN junction connected with the upper electrode. 
     
     
       6. The fingerprint identifying module according to  claim 1 , wherein the lower electrode is made of a transparent conductive material. 
     
     
       7. The fingerprint identifying module according to  claim 1 , wherein the upper electrode is made of metal. 
     
     
       8. The fingerprint identifying module according to  claim 1 , wherein the fingerprint identifying module further comprises a dielectric layer, the TFT and the PN junction are isolated from each other by the dielectric layer. 
     
     
       9. The fingerprint identifying module according to  claim 1 , wherein the scanning line and the sensing line are arranged in a same layer as the source electrode of the TFT. 
     
     
       10. The fingerprint identifying module according to  claim 1 , wherein the PN junction comprises an N-type region, a P-type region and an intrinsic region; one end of the PN junction is the N-type region, and the other end of the PN junction is the P-type region. 
     
     
       11. A display device, comprising a display panel and the fingerprint identifying module according to  claim 1  which is provided on the display panel. 
     
     
       12. The display device according to  claim 11 , wherein the display panel comprises a plurality of sub-pixel regions; a projection of the upper electrode on the display panel is located between adjacent sub-pixel regions. 
     
     
       13. A method of fabricating a fingerprint identifying module, comprising:
 providing a substrate; 
 forming a lower electrode on the substrate; 
 forming a photocurrent generating unit on the lower electrode; 
 forming an upper electrode on the photocurrent generating unit, the photocurrent generating unit comprising a PN junction, a scanning line and a sensing line, one end of the PN junction being connected with the upper electrode, and the other end of the PN junction being connected with the lower electrode; and 
 forming a thin film transistor (TFT) between the upper electrode and the lower electrode, wherein the upper electrode is connected with a drain electrode of the TFT, the lower electrode is connected with the scanning line; the scanning line is configured for inputting a first fingerprint identifying voltage to the lower electrode while the TFT is turned on; the TFT is configured for being turned on under an effect of a gate voltage; a source electrode of the TFT is connected with the sensing line, and the sensing line is configured for inputting a second fingerprint identifying voltage to the source electrode of the TFT. 
 
     
     
       14. A method of driving the fingerprint identifying module according to  claim 1 , the method comprising:
 inputting a first fingerprint identifying voltage to the lower electrode in a mode of row-by-row scanning at fingerprint identifying stage; 
 inputting a second fingerprint identifying voltage to the upper electrode in a currently scanned row, and acquiring a feedback voltage formed by combining a photocurrent generated in the photocurrent generating unit with the second fingerprint identifying voltage; and 
 determining whether the lower electrode corresponds to a valley or a ridge of a fingerprint according to the feedback voltage. 
 
     
     
       15. The method according to  claim 14 , further comprising:
 inputting a touch signal to the lower electrode at touch sensing stage.